Methods and appratus for monitoring rotation of an infusion pump driving mechanism

ABSTRACT

An infusion system, method and device for delivering therapeutic fluid to the body of a patient are disclosed. The device includes a dispensing unit having a peristaltic pump for dispensing therapeutic fluid to the body of the patient. The peristaltic pump includes a driving mechanism. The device further includes a monitoring mechanism ( 112, 114 ) for monitoring operation of the driving mechanism and dispensing of therapeutic fluid to the body of the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 60/928,751, filed May 11, 2007 and incorporatesdisclosure of this application herein by reference in its entirety.

The present application also claims priority to U.S. Provisional PatentApplication No. 60/928,815, filed on May 11, 2007, and entitled “APositive Displacement Pump”, and U.S. Provisional Patent Application No.60/928,750, filed on May 11, 2007, and entitled “Fluid Delivery Device”.This application incorporates disclosures of each of these applicationsherein by reference in their entireties.

The present application also relates to the co-owned/co-pending U.S.patent application Ser. No. ______, and International Patent ApplicationNo. PCT/IL08/______, both filed on the even date herewith, and bothentitled “A Positive Displacement Pump”, and U.S. patent applicationSer. No. ______, and International Patent Application No.PCT/IL08/______, both filed on the even date herewith, and both entitled“Fluid Delivery Device”. The disclosures of these applications areincorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention generally relates to apparatuses and methods forsustained medical infusion of fluids, and more particularly to aportable infusion device that can be attached to a patient's body andaccurately dispense fluids to the patient's body. Particularly, thepresent invention relates to an infusion pump that includes two parts: adisposable part and a reusable part. More particularly, the presentinvention relates to apparatus and methods for monitoring rotation ofthe infusion pump driving mechanism components.

BACKGROUND OF THE INVENTION

Medical treatment of several illnesses requires continuous drug infusioninto various body compartments, such as subcutaneous and intra-venousinjections. Diabetes mellitus patients, for example, requireadministration of varying amounts of insulin throughout the day tocontrol their blood glucose levels. In recent years, ambulatory portableinsulin infusion pumps have emerged as a superior alternative tomultiple daily syringe injections of insulin. These pumps, which deliverinsulin at a continuous basal rate as well as in bolus volumes, weredeveloped to liberate patients from repeated self-administeredinjections, and allow them to maintain a near-normal daily routine. Bothbasal and bolus volumes must be delivered in precise doses, according toindividual prescription, since an overdose or under-dose of insulincould be fatal.

Several ambulatory insulin infusion devices are currently available onthe market. Mostly, these devices have two portions: a reusable portionthat contains a dispenser, a controller and electronics, and adisposable portion that contains a syringe-type reservoir, a needleassembly with a cannula and a penetrating member, and fluid deliverytube. Usually, the patient fills the reservoir with insulin, attachesthe needle and the delivery tube to the exit port of the reservoir, andthen inserts the reservoir into the pump housing. After purging air outof the reservoir, tube and needle, the patient inserts the needleassembly, penetrating member and cannula, at a selected location on thebody, and withdraws the penetrating member. To avoid irritation andinfection, the subcutaneous cannula must be replaced and discarded after2-3 days, together with the empty reservoir. Examples of firstgeneration disposable syringe-type reservoir and tubes were disclosed inU.S. Pat. No. 3,631,847 to Hobbs, U.S. Pat. No. 3,771,694 to Kaminski,U.S. Pat. No. 4,657,486 to Stempfle, and U.S. Pat. No. 4,544,369 toSkakoon. The driving mechanism of these devices is a screw-threadeddriven plunger controlling the programmed movement of a syringe piston.

Other dispensing mechanisms have been also discussed, includingperistaltic positive displacement pumps, in U.S. Pat. No. 4,498,843 toSchneider and U.S. Pat. No. 4,715,786 to Wolff. These devices representan improvement over multiple daily injections, but nevertheless, theyall suffer from several drawbacks, one of the main drawbacks is itslarge size and weight of the device, caused by the configuration and therelatively large size of the driving mechanism of the syringe and thepiston. This relatively bulky device has to be carried in a patient'spocket or attached to the belt. Consequently, the fluid delivery tube islong, usually longer than 60 cm, in order to permit needle insertion atremote sites of the body. These uncomfortable bulky devices with a longtube are rejected by the majority of diabetic insulin users, since theydisturb regular activities, such as sleeping and swimming. Furthermore,the effect of the image projected on a body of a teenager isunacceptable. In addition, the delivery tube excludes some optionalremote insertion sites, like buttocks, arms and legs. To avoid theconsequences of long delivery tube, a new concept, of second generationpump, was proposed. This concept includes a remote controlled skinadherable device with a housing having a bottom surface adapted tocontact patient's skin, a reservoir disposed within the housing, and aninjection needle adapted to communicate with the reservoir. These skinadherable devices should be disposed every 2-3 days similarly toavailable pump infusion sets. These devices were disclosed at least inU.S. Pat. No. 5,957,895 to Sage, U.S. Pat. No. 6,589,229 to Connelly,and U.S. Pat. No. 6,740,059 to Flaherty. Additional configurations ofskin adherable pumps were disclosed in U.S. Pat. No. 6,723,072 toFlaherty and U.S. Pat. No. 6,485,461 to Mason. These devices also haveseveral limitations: they are bulky and expensive, their high sellingprice is due to the high production and accessory costs, and the usermust discard the entire device every 2-3 days, including relativelyexpensive components, such as driving mechanism and other electronics.

e.g., i.e., i.e., i.e., e.g., As mentioned above, the volume of fluidinfused to the patient must be delivered in precise doses, according toindividual prescription, since an overdose or underdose of insulin couldbe fatal. The reliability of the infusion pump can be greatly enhancedby monitoring the rotation of the driving mechanism of the infusionpump.

Existing rotation monitoring devices include optic encoders comprisingof a large disc mounted on the motor shaft and several sets of lightemitting diodes (“LEDs”) and light detectors, as disclosed, for example,in U.S. Pat. No. 6,078,273 to Hutchins. These encoders occupy a largespace and hence are not suitable for a miniature infusion pump. Moreoverthe use of several sets of LEDs and light detectors, which is highlyexpensive, is not required for the high precision of a stepper motor.

Furthermore, when the encoder is located on the motor shaft it monitorsonly the rotation of the motor itself, and cannot directly monitorrotations of shafts and gears. Moreover, it does not detect occurrencesof electro-mechanical disassociation due to breakage of gears, dust,etc.

Another problem which exists in rotary peristaltic pumps is that theresulting delivery of fluid occurs in a series of pulses or surges, thefrequency of which is equal to the frequency of the passage ofsuccessive rollers in contact with the delivery tube. This flow patternis inherent in conventional rotary peristaltic pumps. The effect is thatfluid is delivered at a widely varying rate during a pump cycle and thiscan be unacceptable in infusion procedures in which uniformity ofdelivery rate is a requirement (e.g., insulin pumps). Moreover, thecontinuous change in flow rate can cause instability in sensitivefeedback control systems which are designed to ensure that fluid isdelivered at a constant rate. It was found that during the passage ofeach peristaltic pump roller in contact with the delivery tube, constantflow was maintained through a portion of the motor cycle, immediatelyfollowed by a period of no flow at all in the downstream or positivedirection. During this dwell period, there is often some evidence ofnegative flow.

This means that in normal operation, the pump is delivering no fluid fora portion of its operating time and is delivering fluid at a higher ratethan the average for the other cycle portion.

Having frequent periods in which there is no fluid flowing downstream,i.e., towards the patient's body, is extremely hazardous when dealingwith therapeutic fluid such as insulin. When an insulin pump is set toits minimal flow rate, it is likely that the patient will not receiveany insulin at all.

An example of a control apparatus for the drive motor of a peristalticpump for maintaining a uniform flow rate is disclosed in, for example,U.S. Pat. No. 4,604,034 to Wheeldon that discusses a control apparatusemploying a photo sensor. The control apparatus, however, was notspecified as to how it can be materialized, i.e., what the possiblelocations of the photo sensor are, if it can be employed in aminiature-size infusion pump, etc. Moreover, employment of a differenttype of sensor other than a photo sensor was not discussed.

i.e., e.g.,

SUMMARY OF THE INVENTION

To overcome the deficiencies of the above conventional devices, someembodiments of the present invention are directed to an improved methodand device for monitoring the rotation of a driving mechanism (i.e.,motor, gears, shafts, etc.) capable of detecting occurrences ofelectro-mechanical disassociation. In some embodiments, the presentinvention is directed to an appropriate size (e.g., miniature) devicefor monitoring the rotation of a driving mechanism. The presentinvention also provides an efficient and cost-effective device formonitoring the rotation of a driving mechanism.

In some embodiments, the present invention is directed to anappropriately-sized device for monitoring the rotation of a drivingmechanism of an infusion pump. The present invention also capable ofmonitoring the rotation of a driving mechanism of an infusion pump thatcan be attached to the patient's skin. In some embodiments, theappropriately-sized device for monitoring the rotation of a drivingmechanism of an infusion pump includes two parts, e.g., a reusable partand a disposable part. In some embodiments, the device can be attachedto and detached from the skin.

In some embodiments, the present invention is directed to anappropriately-sized device for monitoring the rotation of a rotary wheelof a positive displacement peristaltic pump and for providing a solutionto the problem of having a no-flow or backflow of fluid as well asminimizing its effects on fluid delivery to the patient.

As can be understood by one skilled in the art, the appropriately-sizedterm can refer to a miniature size or any other size suitable for thepurposes as discussed in the present application.

Some embodiments of the present invention relate to a method and adevice for monitoring the rotation of an infusion pump driving mechanism(i.e., motor, gears, shafts, etc.).

In some embodiments, the present invention relates to a self-correctionmechanism operating via a feedback control system that accounts for theoccurrence of at least one of the following conditions: motormalfunction, electrical wire(s) disconnection, software and/orelectronics error(s), battery voltage drop, and/or electro-mechanicaldisassociation due to breakage of gears, dust, etc.

In some embodiments, the present invention relates to a method and asystem for alerting the patient if the above correction attempts fail.

In some embodiments, the present invention relates to a method forpreventing or at least minimizing the occurrence(s) of no-flow orbackflow in a positive displacement peristaltic pump and minimizing itseffects on fluid delivery to the patient.

Some embodiments of the present invention relate to an infusion pump'sdriving mechanism, which may include DC motor, stepper motor, SMAactuator, etc. It should be noted that in stepper motors, detection ofelectro-mechanical disassociation is a challenge because motor rotationcan be ceased without concomitant voltage or current changes and for thepatient it will seem that the motor continues to work properly.

Inefficiency of an infusion pump driving mechanism could be lifethreatening because of the likely possibility of drug (e.g., insulin)under-dosing. Thus, it would be important to monitor the rotation of aninfusion pump's driving mechanism (especially, one employing a steppermotor), and to apply self-correction or alert the patient of incorrectdrug delivery in the occurrence of motor malfunction orelectro-mechanical disassociation.

Some embodiments of the present invention provide a solution formonitoring the rotation of a miniature infusion pump's driving mechanismin order to ensure that the patient is provided with required amounts oftherapeutic fluid.

In some embodiments, the present invention relates to systems andmethods for monitoring rotation of the driving mechanism of a miniatureinfusion pump having two parts: a reusable part and a disposable part,which can be adhered to the skin of the patient and can be attached toand detached from the skin.

Some embodiments of the present invention provide a solution formonitoring the rotation of different components of the infusion pump'sdriving mechanism so that it is possible to detect occurrences ofelectro-mechanical disassociation as well as motor malfunction.

Some embodiments of the present invention relate to systems and methodsfor preventing or at least minimizing the occurrence(s) of backflow inpositive displacement peristaltic pumps, and minimizing its effects onfluid delivery to the patient.

Some embodiments of the present invention are directed to aminiature-size, cost-effective rotation monitoring devices, such as onewhich includes an encoder wheel, at least one light emitting diode(“LED”) and at least one light detector located at opposite sides of theencoder wheel. The device monitors the rotation of at least onecomponent of a driving mechanism (i.e., motor, gear, shaft, etc.),maintains required rotation rate and alerts the user if necessary.

Embodiments of the present invention also relate to a miniature-size,cost-effective rotation monitoring devices, such as one which includes aLED and a light detector located at opposite sides of the rotary wheel,when employing a positive displacement peristaltic pump. The devicemonitors the rotation of the rotary wheel and increases the motor speedduring no-flow or backflow periods of the rotation cycle. For example,when employing a stepper motor, the acceleration is for a predeterminednumber of pulse trains during the no flow or backflow cycle period.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a-c illustrate exemplary single-part patch unit, two-part patchunit and a remote control unit, according to some embodiments of thepresent invention.

FIGS. 2 a-b illustrate an exemplary single-part patch unit (shown inFIG. 2 a) and an exemplary two-part patch unit (shown in FIG. 2 b)employing a peristaltic pumping mechanism, according to some embodimentsof the present invention.

FIG. 3 illustrates exemplary components of the reusable part of theperistaltic dispensing unit, according to some embodiments of thepresent invention.

FIG. 4 illustrates an exemplary driving mechanism of the infusion pump,a LED and a light detector located on the opposite sides of thesecondary gear, according to some embodiments of the present invention.

FIG. 5 illustrates exemplary driving mechanism of the dispensing unit,components of the printed circuit board (PCB), and connections to theLED and light detector, according to some embodiments of the presentinvention.

FIG. 6 a is a longitudinal cross-sectional view of the secondary gearwhen one of its apertures is aligned with the LED and the lightdetector.

FIG. 6 b is a longitudinal cross-sectional view of the secondary gearwhen none of its apertures are aligned with the LED and the lightdetector.

FIGS. 7 a-d are perspective and front views of the secondary gearcolored half white and half black and adjacently-situated LED and lightdetector.

FIG. 8 illustrates exemplary reusable part components of a peristalticdispensing unit, according to some embodiments of the present invention.

FIG. 9 illustrates exemplary driving mechanism of the dispensing unit,an encoder wheel fixed on the worm shaft and a photointerruptor,according to some embodiments of the present invention.

FIGS. 10 a-e are perspective and side views of an encoder wheel and aphotointerruptor.

FIGS. 11 a-d are front and perspective views of a round disc coloredhalf white and half black and adjacently-situated LED and lightdetector.

FIGS. 12 a-d illustrate an exemplary sharpened worm shaft and anadjacently-situated LED and light detector, according to someembodiments of the present invention.

FIGS. 13 a-c illustrate an exemplary secondary gear with two magnetslocated either on the gear or within the gear's apertures ordepressions, and a “Hall effect sensor”, according to some embodimentsof the present invention.

FIG. 14 illustrate an exemplary worm shaft with two magnets located atits tip and a “Hall effect sensor”, according to some embodiments of thepresent invention.

FIG. 15 illustrates exemplary components of the reusable part of asyringe-type infusion pump, according to some embodiments of the presentinvention.

FIG. 16 is a block diagram of the feedback process, according to someembodiments of the present invention.

FIGS. 17 a-d illustrate several exemplary consecutive positions of therollers of a positive displacement peristaltic pump during the pumpingcycle, according to some embodiments of the present invention.

FIG. 18 is a characteristic graph of a fluid flow rate (volume of fluiddelivered over time) in a positive displacement peristaltic pump,according to some embodiments of the present invention.

FIG. 19 illustrates exemplary LED and light detector located at oppositesides of the rotary gear, according to some embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

To avoid the price limitation and to extend patient customization, nextgeneration skin adherable dispensing patch unit (“dispensing unit” or“patch unit”) was devised. An example of such device is discussed in aco-pending/co-owned U.S. patent application Ser. No. 11/397,115 andInternational Patent Application No. PCT/IL06/001276, disclosures ofwhich are incorporated herein by reference in their entireties. Thisnext generation device is a dispensing unit having two parts:

-   -   Reusable part—containing the at least a portion of driving and        pumping mechanism, electronics and other relatively expensive        components.    -   Disposable part—containing cheap, discardable components such as        reservoir and tubes.    -   The device also includes a power supply, such as, on or more        batteries. The batteries can be disposed in the disposable part,        or reusable part, or the power supply can be shared by the        disposable part and the reusable part.

This concept provides possibility for a cost-effective skin adherableinfusion device and allows diverse usage of the device, e.g., the use ofvarious reservoir sizes, various needle and cannula types andimplementation of versatile operational modes. This generation ofinfusion pumps allows for various applicable types of pumping mechanismsfor the two-part device configuration. The delivery mechanism can be theperistaltic positive displacement pumping mechanism also discussed inco-pending/co-owned U.S. patent application Ser. No. 11/397,115 andInternational Patent Application No. PCT/IL06/001276.

Alternative driving mechanisms, which can be applied in any one of thevarious pumping mechanisms, may include DC motor, stepper motor, ShapeMemory Alloy (SMA) actuator, etc. An exemplary driving mechanismincludes a stepper motor due to its ability to be accurately controlledin an open loop system, i.e., no position feedback is needed, andtherefore it is less costly to control.

Stepper motors may be activated discretely by series of sequential inputpulses, i.e., “pulse trains”, applied by the central processing unit(CPU), and transmit force and motion (i.e., torque) to the drivingmechanism (e.g., “gear trains”).

FIGS. 1 a-c show an exemplary fluid delivery device having a dispensingunit (10) and a remote control unit (40), according to some embodimentsof the present invention. In some embodiments, the dispensing unit (10)can include a single part (as illustrated in FIG. 1 b) or two parts (asillustrated in FIG. 1 c). In the two-part embodiment, the dispensingunit includes a reusable part (100) and a detachably-connectabledisposable part (200). The remote control unit (40) communicates withthe dispensing unit (10) and includes a display, control button(s), aprocessor, a memory, and any other components for communicating with theunit (10). The remote control unit (40) can communicate with the unit(10) using wired, wireless, RF, or any other suitable methods ofcommunication. The remote control unit (40) can be any remote control, acellular telephone, an iPod, a PDA, or any other suitable device.

The dispensing unit (10) may employ different dispensing mechanisms,such as a syringe-type reservoir with a propelling plunger, peristalticpositive displacement pumps, or any other suitable dispensing mechanism.The following description will refer to peristaltic positivedisplacement pumps for illustrative purposes only and is not intended tolimit the scope of the present invention. As can be understood by oneskilled in the art, other dispensing can be used with the presentinvention.

FIG. 2 a shows an exemplary single-part dispensing unit (10), accordingto some embodiments of the present invention. The single-part dispensingunit (10) has a single housing in which a peristaltic pump is employedfor dispensing fluid to the body of a patient. The unit (10) includes areservoir (220), a fluid delivery tube (230), a rotary wheel (110), anoutlet port (213), a stator (190) elastically supported by a spring(191), a motor (120), electronics (130) (which can include a printedcircuit board (“PCB”) and/or other electronic components; throughout thefollowing description, “electronics (130)” and “PCB (130)” will be usedinterchangeably and refer to the same element), an energy supply means(240), and control buttons (15 a) and (15 b). The reservoir (220) is influid communication with the outlet port (213) via the fluid deliverytube (230). The fluid delivery tube (230) is disposed between the rotarywheel (110) and the stator (190). The fluid delivery tube (230) issqueezed between the stator (190) that is elastically supported by thespring (191) and the rotary wheel (110) during delivery of the fluid viathe fluid delivery tube (230). The motor (120) drives rotation of therotary wheel (110). The energy supply means (240) (e.g., a battery)provides power to the unit (10) and to the motor (120). Electronics(130), which can include a processor, a memory, and other components,are coupled to the motor (120) and control buttons (15), and providefurther control of fluid dispensing to the patient. The electronics(130) can also enable communication with the remote control unit (40)(not shown). The electronics (130) can determine the rate of fluiddelivery to the patient, e.g., basal rate and/or bolus rate. The buttons(15) control electronics (130), turn the device on/off, and can provideany other desired functions (e.g., programming of the unit (10)). Thefluid is delivered from the reservoir (220) through the delivery tube(230) to the outlet port (213).

The rotary wheel (110) includes a rotary gear (not shown), a rotaryplate (not shown), and rollers (not shown). Rotation of the rotary wheel(110) and pressing of the rollers against one side of the fluid deliverytube (230), which is being pressed on by the stator (190) on the otherside, periodically positively displaces the fluid within the deliverytube (230) by virtue of a peristaltic motion. An example of a suitablepositive displacement pump is disclosed in co-pending/co-owned U.S.patent application Ser. No. 11/397,115 and International PatentApplication No. PCT/IL06/001276, the disclosures of which areincorporated herein by reference in their entireties. A motor (120),such as a stepper motor, a DC motor, a SMA actuator or the like, rotatesthe rotary wheel (110) and is controlled by the electronic componentsschematically designated as electronics (130). As stated above, theelectronic components include a controller, a processor and atransceiver. The energy supply means (240) can be one or more batteries.Infusion programming can be carried out by a remote control unit (notshown) or by manual buttons (15) provided on the dispensing unit (10).

FIG. 2 b shows an exemplary two-part dispensing unit (10), according tosome embodiments of the present invention. The unit (10) has a reusablepart (100) and a disposable part (200), wherein each part is containedwithin its own housing. The reusable part (100) includes a positivedisplacement pump provided with the rotary wheel (110), the motor (120),the PCB (130) and manual buttons (15). The disposable part (200)includes the reservoir (220), the delivery tube (230), the energy supplymeans (240), the outlet port (213) and the stator (190).

In this embodiment, fluid dispensing is possible after connecting thereusable part (100) with the disposable part (200). Once the parts areconnected, fluid dispensing can be performed in a similar fashion as inthe single-part unit (10) shown in FIG. 2 a. An example of thisarrangement is disclosed in the co-pending/co-owned U.S. patentapplication Ser. No. 11/397,115 and International Patent Application No.PCT/IL06/001276, the disclosures of which are incorporated herein byreference in their entireties. As can be understood by one skilled inthe art, all embodiments of rotation monitoring means describedhereafter can be implemented in a single-part dispensing unit, atwo-part dispensing unit or a multi-part dispensing unit.

FIG. 3 shows an embodiment of the reusable part (100), according to someembodiments of the present invention. The driving mechanism of thereusable part (100) includes the rotary wheel (110) and the motor (120).The driving mechanism further includes a pinion (122), a secondary gear(124), a worm (126), and a shaft (128). The worm (126) is coupled to theshaft (128), which is in turn is coupled to the secondary gear (124).The secondary gear (124) is coupled to the pinion (122) that is coupledto the motor (120). The worm (126) is coupled to the rotary wheel (110).Upon application of power from the energy supply means (240) (not shownin FIG. 3), the motor (120) causes rotation of the secondary gear (124)via pinion (122). The pinion (122) and the secondary gear (124) caninclude teeth that are configured to mate with each other and therebycause rotational motion. As the secondary gear (124) is coupled to theshaft (128), rotation of the secondary gear (124) causes rotation of theshaft (128), thereby causing rotation of the worm (126). The worm (126)can be similar to a thread, whose rotational motion is translated to therotary wheel (110). The rotary wheel (110) can include a plurality ofteeth that mate with the threads on the worm (126). The reusable partfurther includes the PCB (130), and manual buttons (15) and an alertingcomponent (17). As stated above, the manual buttons (15) canactivate/deactivate operation of the driving mechanism. Further detailsof the above arrangement are illustrated in FIG. 4 and are discussedbelow.

The driving mechanism of the reusable part (100) further includes asource of energy, such radiation, electromagnetic radiation, infraredradiation (“IR”), electrochemical energy, electromechanical energy,mechanical energy, or any other source of energy. In some embodiments,the source of such energy is an LED (112) and an electromagneticradiation detector (114) that are disposed proximal to the secondarygear (124). In the further description, “source of electromagneticradiation” will be referred-to as “light source” or as “LED”, and“electromagnetic radiation detector” will be referred-to as “lightdetector”. The LED (112) and the light detector (114) perform monitoringof the rotation of the secondary gear (124) of the driving mechanism.The LED (112) and the light detector (114) can be configured to belocated on the opposite sides of the secondary gear (124), whereby LED(112) emits light toward the light detector (114) and interruption ofthe light emitted by LED (112) by the secondary gear (124) is detectedby the light detector (114). The light detector (114) can be aphototransistor that can detect light emitted by the LED (112). Upondetection of the interruption of the emitted light, a signal isgenerated and then sent to the processor for processing. Such detectionis further discussed below.

As can be understood by one skilled in the art, the LED (112) and thelight detector (114) may be located on opposite sides of any rotatingcomponent which is a part of the driving mechanism of the dispensingunit (10), for example, the rotary gear (110). In the followingdescription, the arrangement of the LED (112) and the light detector(114) will be discussed for exemplary, illustrative purposes and is notintended to limit the scope of the present invention. As can beunderstood by one skilled in the art, such arrangement is applicable toany other component in the dispensing unit (10).

FIG. 4 shows further detail of the driving mechanism of the dispensingunit (10) as shown in FIG. 3. As stated above, The motor (120) rotatesthe pinion (122), which is coupled to the secondary gear (124). Theteeth of the pinion (122) are meshed with the teeth of the secondarygear (124), so that the teeth of the pinion (122) transmit torque to theteeth of the secondary gear (124). In some embodiments, the secondarygear (124) then rotates in a direction opposite to the direction ofrotation of the pinion (122). In some embodiments, the rotation isaccomplished at an exemplary gear ratio of 3:1. The secondary gear (124)and the worm (126) are both mounted on the shaft (128), as such they arerotated at the same rotational velocity. The worm (126) is coupled tothe teeth of the rotary gear plate (106) of the rotary wheel (110). Asthe worm (126) rotates, it transmits torque to the rotary gear plate(106), thereby rotating it. In some embodiments, the plane of rotationof the worm (126) is perpendicular to the plane of rotation of therotary gear plate (106).

As illustrated in FIG. 4, the rotary wheel (110) includes a rollersupporting plate 105) to which one or more rollers (101 a), (101 b) (insome embodiments, there can be four rollers; the additional two rollersare not shown in FIG. 4) are coupled. The roller supporting plate (105)is further coupled to rotary gear plate (106) and is capable of rotatingaround its axis, as indicated by the rotational arrow A in FIG. 4. Ascan be understood by one skilled in the art, the rotary wheel (110) canrotate in any desired direction. The rollers (101) (in the followingdescription “rollers (101)” will refer to the plurality of rollers and“roller (101 a)”, “roller (101 b)”, etc. will refer to individualrollers) are rotationally secured to the roller supporting plate (105)and are placed between the roller supporting plate (105) and the rotarygear plate (106), as illustrated in FIG. 4. This means that the rollers(101) are capable of rotating as the rotary wheel (110) rotates aroundits axis. The combination of the roller supporting plate (105) and therotationally-secured rollers (101) has a smaller diameter than therotary gear plate (106). Such arrangement prevents interference of therotary gear plate (106) with dispensing of the fluid through thedelivery tube (not shown in FIG. 4). Further, the rollers (101) aredisposed around the center of the rotary wheel (110). As the rotarywheel (110) rotates, the rollers (101) press against the delivery tube(not shown in FIG. 4), which is sandwiched between the rollers (101) andthe stator (not shown in FIG. 4). The stator is applied to the deliverytube in way so that it does not interfere with the rotation of therotary gear plate (106). Squeezing of the delivery tube by the rollers(101) periodically positively displaces fluid inside the delivery tubeby virtue of the peristaltic motion. Based on the direction of rotationof the rotary wheel, the fluid inside the fluid delivery tube isdisplaced in the appropriate direction. As can be understood by oneskilled in the art, the axis of rotation of the rotary wheel (110) canbe coupled to the housing of the reusable unit (100).

As stated above, to monitor rotation of the secondary gear (124), thesecondary gear (124) includes two equally disposed apertures (127) and(127′). The apertures (127) allow the passage of light emitted by theLED (112) through the secondary gear (124) to the light detector (114).As can be understood by one skilled in the art, the LED (112) and thelight detector (114) both have appropriate leads which are soldered tothe PCB (130) (not shown in FIG. 4). The LED (112) and the lightdetector (114) are so positioned within the housing of the reusable unit(100) and adjacent to the secondary gear (124) as to allow passage oflight from the LED (112) to the light detector (114).

As can be understood by one skilled in the art, there may be only oneaperture (127) in the secondary gear (124) or more than two apertures(127) which can be equally spaced, and the apertures (127) may be of anysize and shape. In some embodiments, the number of apertures determinesthe resolution of the monitoring. In the embodiment where the secondarygear (124) includes one aperture, signals transmitted by the lightdetector (114) indicate only when one full turn of the secondary gear(124) has been completed. In the embodiment, where the secondary gear(124) has two apertures, signals transmitted by the light detector (114)indicate when one-half of a turn of the secondary gear (124) has beencompleted. In multiple-aperture embodiments, the signals transmitted bythe light detector (114) indicate when a part of a turn of the secondarygear (124) has been completed. Rotation of the secondary gear (124) anddetection of rotational position of the gear (124) by the light detector(114) determines an amount of fluid to be dispensed through the fluiddelivery tube (not shown) to the patient.

As stated above, upon rotation of the secondary gear (124) and alignmentof the apertures (127) with the LED (112) and light detector (124), thelight emitted by the LED (112) passes through the aperture (127) and isreceived by the light detector (124). Upon receipt of the emitted lightby the light detector (124), the light detector (124) generates a signalthat is sent to a processor or CPU (not shown but discussed below withregard to FIG. 5) disposed on the PCB (130), which along with othercomponents processes this signal (in the following description and forease of discussion, unless otherwise noted, the reference to “PCB (130)”will refer to appropriate components of the PCB (130), such as theprocessor, memory, etc. that perform functions that are being discussed,such as processing, determining, and others). Upon processing of thesignal, the PCB (130) determines how many turns and/or portion of theturn the secondary gear (124) made and correlates that to a particulardosage of therapeutic fluid delivered to the patient. In someembodiments, the use of the secondary gear (124) or any other rotatingcomponent that is a part of the driving mechanism as an encoder wheel(or encoder vane) for the purposes of monitoring of an amount of fluidbeing delivered is highly advantageous as it obviates the need for anadditional space for monitoring components of the driving mechanism. Asstated above and as can be understood by one skilled in the art, the LED(112) and the light detector (114) can be placed anywhere on anycomponent of the driving mechanism or other carrier/platform such as thePCB, and monitor rotation of other components.

FIG. 5 is a perspective view of a dispensing unit's driving mechanismand the main components of the. PCB (130). The LED (112) and the lightdetector (114) both have respective electrical leads (199) and (198)that are connected (e.g., soldered) to the PCB (130). The LED (112) andthe light detector (114) are powered by at least one battery provided inthe disposable or the reusable part (not shown in FIG. 5). The PCB (130)further includes a central processing unit (“CPU”) (650) that activatesthe LED (112) and the light detector (114). Upon activation, the lightdetector (114) transmits signals (i.e., upon detection of lighttransmitted by the LED (112)) either directly to the CPU (650) or toanother electronic component, e.g., a comparator (not shown in FIG. 5)for processing. As can be understood by one skilled in the art, the LED(112) and the light detector (114) can be located on different sides andnot necessarily be arranged as shown in FIG. 5.

The motor (120) is coupled to the PCB (130) via electrical leads (125).The leads (125) provide power to the motor (120) from the energy supplymeans (not shown in FIG. 5). Additionally, the leads (125) providecommands from the CPU (650) to the motor, e.g., to rotate the pinion(122) at a certain speed and/or direction and/or stop.

FIG. 6 a is a longitudinal cross-sectional view of the secondary gear(124) having two equally disposed apertures (127) and (127′). Thesecondary gear (124) is rotated by the pinion (122), which is rotated bythe motor (120). As illustrated in FIG. 6 a, the LED (112) and the lightdetector (114) are located below the shaft (128) and as further shown,the LED (112) transmits light through aperture (127) toward lightdetector (114). Specifically, the LED (112) emits light (1000)(indicated by an arrow) toward the secondary gear (124). When anaperture (127) in the secondary gear (124) is aligned with the LED (112)and the light detector (114) located at the opposite side of thesecondary gear (124), the light (1000) passes through the aperture (127)and is detected by the light detector (114).

As illustrated in FIG. 6 a, the light (1000) emitted by the LED (112)can pass directly from the LED (112) through an aperture (127) to thelight detector (114). This is so in the case where the LED (112) and thelight detector (114) face each other on the opposite sides of the gear(124). In some embodiments, a plurality of mirrors/reflecting surfacescan be used to allow reflection of the light in order for it to be aimedto pass through the aperture (127). These embodiments are useful in theevent, where the LED (112) and the light detector (114) are facing invarious directions and/or are not necessarily disposed adjacent to thesecondary gear (124) (or any other component of the driving mechanism).Upon detection of the light (1000), the light detector (114) generates asignal and transmits such signal to CPU (650) (not shown) forprocessing. Upon receipt of the signal, the CPU (650) determines howmany turns and/or portions of a turn, the secondary gear (124) (or anyother component) has completed.

FIG. 6 b is another longitudinal cross-sectional view of the secondarygear (124). As shown in FIG. 6 b, none of the apertures (127) in thesecondary gear (124) are aligned with the LED (112) and the lightdetector (114). In this case, the light (1000) cannot pass through theapertures (127) and thus, reflected away from the secondary gear (124).Hence, no light is detected by the light detector (114). Since no lightis detected by the light detector (114), the detector (114) does notgenerate a signal for transmission to the CPU (650).

As can be understood by one skilled in the art, the LED (112) can eitheremit light continuously or, in order to minimize energy consumption, canbe activated (either by the CPU (650) or any other component)periodically according to a predetermined time schedule. When using astepper motor, for example, the LED (112) may be activated by the CPU(650) only when the CPU (650) sends a pulse train to the motor (120). Insome embodiments, the present invention can include a DC motor, an SMAactuator, or any other type of motor.

FIGS. 7 a-d show another exemplary monitoring system of the drivingmechanism, according to some embodiments of the present invention. Inthis embodiment, the secondary gear (124) is colored dichotomously,e.g., half white and half black, as shown in FIG. 7 a. The lightdetector (114) is situated adjacent to the LED (112) and both are facingthe secondary gear (124). The light detector (114) and the LED (112) maybe two separately located components or fixed adjacently on a commonsupport frame made of an opaque-material package. Both the LED (112) andthe light detector (114) can have leads (similar to those shown in FIG.5), which are coupled (e.g., soldered) to the PCB (130). When the light(1000) emitted by the LED (112) hits the white half of the secondarygear (124), the light (1000) is reflected from the secondary gear (124)and then detected by the light detector (114). FIG. 7 b is a front viewof the secondary gear (124) when the light (1000) emitted by the LED(112) hits the white half of the secondary gear (124). The light (1000)is reflected from the secondary gear (124) and then collected by thelight detector (114). FIGS. 7 c-d are perspective and front views,respectively, of the secondary gear (124) at the time the light (1000)emitted by the LED (112) hits the black half of the secondary gear(124). In such a case, the light (1000) is absorbed by the secondarygear (124), and no light is collected by the light detector (114).

In this embodiment, the LED (112) either emits light continuously, or,in order to minimize energy consumption, is activated by the CPU (650)periodically according to a predetermined time schedule. When using astepper motor, for example, the LED (112) may be activated by the CPU(650) when the CPU (650) sends a pulse train to the motor (not shown).

FIG. 8 illustrates an embodiment of the reusable part (100) having thecomponents discussed above (i.e., the rotary wheel (110), the motor(120), the PCB (130), the pinion (122), the secondary gear (124), theworm (126), the shaft (128), the manual buttons (15) and the alertingcomponent (17)), where monitoring of the driving mechanism is carriedusing a photointerruptor (113). The photointerruptor (113) includes acommon support frame that secures the LED (112) and the light detector(114). As illustrated in FIG. 8, the LED (112) and the light detector(114) are secured in such a way that there is a space S formed betweenthem. The support frame can be manufactured from an opaque-material. Inthis embodiment, the driving mechanism further includes an auxiliaryelement affixed to a rotating component (e.g. pinion, secondary gear,shaft, rotary wheel) of the driving mechanism. Optionally, the auxiliaryelement may be an integral part of the rotating component. Such anauxiliary element can be configured for example as an encoder vane (116)affixed to the shaft (128) as shown in FIGS. 8-9. The encoder vane (116)is coupled to the worm (126) via a portion of the shaft (128) thatextends on the opposite side of the worm (126) as the other componentsof the driving mechanism. In some embodiments, the vane (116) has thesame axis of rotation as the shaft (128) and the worm (126). As such,the vane (116) rotates at the same rotational velocity as the shaft(128). The encoder vane (116) can have variable shapes, e.g., asemi-circular shape, a circular shape, or any other shape. Duringrotation of the vane (116), at least a portion of the vane (116) passesthrough space S of the photointerruptor (113). Hence, as the encodervane (116) rotates it passes through the space S between the LED (112)and the light detector (114). As soon as a particular portion of thevane (116) passes through the space S, the light emitted by the LED(112) is interrupted/blocked, hence, the light detector (114) fails todetect any lighted emitted by the LED (112). As no light is detected bythe light detector (114), the detector (114) generates a signalindicating “no detect” condition and sends it to the CPU (650) disposedon the PCB (130) (not shown) for processing. As can be understood by oneskilled in the art, the detector (114) can generate a signal upondetection of the light, i.e., “no detect” condition is a normaloperating condition and no signal is generated, and “detect” conditionis an interrupted condition and signal is generated. As can beunderstood by one skilled in the art, the encoder vane (116) can belocated on either at the end of the shaft (128), as illustrated in FIG.8, or at any other location along the shaft (128), for example, betweenthe secondary gear (124) and the worm (126). Moreover, the encoder vane(116) could be either a separate component mounted on the shaft (128),or an integral part of the shaft (128).

FIG. 9 is a perspective view of the dispensing unit's driving mechanismshown in FIG. 8 above. The encoder vane (116) can be configured as a180° sector (e.g., the vane (116) has a substantially semi-circularshape) and affixed to the shaft (128), as shown in FIG. 8. This meansthat a portion of the vane is non-transparent (for the used range ofwavelengths) and causes interruption of light transmitted by the LED(112). As can be understood by one skilled in the art, the vane (116)can have a circular shape and have one transparent portion and onenon-transparent portion. The light emitted by the LED (112) can passthrough the transparent portion, but cannot pass through thenon-transparent portion. Having a circular shape of the vane (116) canprovide an equal balancing of the vane (116) during rotation and thus,uniform speed of rotation. The LED (112) and the light detector (114)are coupled to the PCB (130) via a plurality of electrical leads (131 a)and (131 b), respectively. The leads (131) can be soldered to the PCB(130). PCB (130), via, for example, its CPU (650),supplies/transmits/receives current and signals via the leads (131). Forexample, electrical current is supplied to the LED (112) to transmitlight toward the light detector (114). The light detector (114) alsotransmits signal via the leads (131) upon detection interruption of thetransmitted light.

FIGS. 10 a-b are perspective and side views, respectively, of theencoder vane (116) and the photointerruptor (113) when the vane (116) islocated outside the space S between the LED (112) and the light detector(114). In this case, the light (1000) emitted by the LED (112) isdetected by the light detector (114). Depending on how the system is setup, upon detection of a no-interruption condition, the light detector(114) does not generate any signals. Alternatively, the light detector(114) can generate a signal indicating no-interruption condition.

FIGS. 10 c-d are perspective and side views, respectively, of theencoder vane (116) and the photointerruptor (113) when the encoder vane(116) is positioned in the space S between the LED (112) and the lightdetector (114). In this case, the encoder vane (116) blocks/interruptsthe light (1000) emitted by the LED (112). Hence, the light (1000) isreflected from the vane (116) and no light is detected by the lightdetector (114). Thus, the light detector (114) can generate a signalindicating interruption condition. The reflected light can be collectedby a separate light detector (not shown), which can generate the signalindicating interruption condition.

As can be understood by one skilled in the art, the present inventioncan encompass use of any number of encoder vanes (116) can be coupled tothe shaft (128) at different locations. Additionally, the encoder vane(116) can have a plurality of sectors. For example, FIG. 10 e shows anencoder vane (116) having one sector (1116) configured as a 180° sector,as shown in FIGS. 9-10 d; FIG. 10 f shows an encoder vane having twosectors (1116, 1116′), wherein each vane is configured to be a 90°sector separated by a 90° angle; and FIG. 10 g shows an encoder vanehaving four sectors (1116, 1116′, 1116″, 1116′″), wherein each sector isconfigured to be a 45° sector separated by a 45° angle.

The number of sectors determines the resolution of the monitoring,whereas when one sector is used, the signals transmitted by the lightdetector (114) will indicate whenever a full turn of the secondary gear(124) has been completed, when two sectors are used the signalstransmitted by the light detector (114) will indicate whenever half aturn of the secondary gear (124) has been completed, and when foursectors are used the signals transmitted by the light detector (114)will indicate whenever one quarter of a turn of the secondary gear (124)has been completed, etc. As can be understood by one skilled in the art,any number of sectors corresponding to any number of detected turns canbe used. Further, monitoring system of the present invention can use anynumber of light sources/light detectors (e.g., LEDs (112), lightdetectors (114)) that can be used with the encoder sector(s) 1116. Useof multiple light sources and/or multiple encoder vanes can provide morecalibrated monitoring of the rotation motion of the driving mechanism.Such sources/detectors/vanes/sectors can be disposed throughout thedriving mechanism.

FIGS. 11 a-b are front and perspective views, respectively, of anotherexemplary monitoring mechanism having a dichotomously colored, e.g.,half white-colored and half black-colored, round disc (118) affixed tothe shaft (128), according to some embodiments of the present invention.The disc (118) rotates with the shaft (128) at the same rotationalvelocity. The light detector (114) is situated adjacent to the LED (112)and both are facing the disc (118), as shown in FIG. 11 b. The lightdetector (114) and the LED (112) used may be two separate components orfixed adjacently on a common support frame made of an opaque-material.Both the LED (112) and the light detector (114) have leads which aresoldered to the PCB (130) (not shown). As the shaft (128) rotates, thedisc (118) rotates, and when the light (1000) emitted by the LED (112)hits the white-colored half of the disc (118), the light (1000) isreflected from the disc (118) and is then detected by the light detector(114). As can be understood by one skilled in the art, the white-coloredportion of the disc (118) can be painted using any reflective color andthe black-colored portion can be painted with any non-reflective color.Alternatively, the white-colored portion can be a mirror that allowsreflection of light emitted by the LED (112), whereas the black-coloredportion can absorb the emitted light or deflected it away so that it isnot detected by the light detector (114).

FIGS. 11 c-d are front and perspective views, respectively, of the disc(118) when the light (1000) emitted by the LED (112) hits theblack-colored half of the disc (118). In such a case, the light (1000)is absorbed by the disc, and no light is detected by the light detector(114). In this embodiment, the LED (112) can emit light continuously or,in order to minimize energy consumption, can be activated by the CPU(not shown) periodically based on a predetermined time schedule. Whenusing a stepper motor, for example, the LED (112) may be activated bythe CPU only when the CPU sends a pulse train to the motor (120). As canbe understood by one skilled in the art, similar to the encoder vanes(116), the disc (118) can have multiple “white-colored” and“black-colored” portions. Further, the monitoring system of the presentinvention can have a multiple number of discs (118) located throughoutthe system for additional monitoring of the rotational motion of thedriving mechanism. As can be understood by one skilled in the art, thedesignations of “white-colored” and “black-colored” are provided forpurely illustrative and non-limiting purposes.

FIG. 12 a shows another exemplary rotation monitoring system of thedriving mechanism, according to some embodiments of the presentinvention. In this embodiment, the distal end of the shaft (128) isconfigured to have a flat portion (111) and a semi-circular portion(119). As the shaft (128) is circular, in some embodiment, a half of thecylindrical portion can be cut away from the distal tip of the shaft(128) to create the flat portion (111), as shown in FIG. 12 a. The lightdetector (114) can be situated adjacent to the LED (112) and both can befurther positioned so that, as the shaft (128) rotates, they are bothfacing either the flat side (111) of the shaft (128) or the circularside of the shaft (128). The light detector (114) and the LED (112) usedmay be two separate components, as illustrated, or secured on a commonsupport frame made of opaque-material. As can be understood by oneskilled in the art, the LED (112) and the light detector (114) haveleads which are soldered to the PCB (130) (not shown). During rotationof the shaft (128), when the flat side (111) of the shaft (128) facesthe LED (112), the light (1000) emitted by the LED (112) is reflectedfrom the flat side (111) and is then detected by the light detector(114), as shown in FIG. 12 b. The flat side (111) can be any reflectivesurface that allows reflection of light, as it is emitted by the LED(112), toward the light detector (114).

FIGS. 12 c-d show the light (1000) hitting the semi-circular side (119)of the shaft (128). In such a case, the light (1000) reflected from theshaft (128) is scattered in different directions, such that only a verysmall portion of the light can be collected by the light detector (114).Even though such minimal amount of light is collected by the lightdetector (114) and the light detector (114) may produce a signalindicating such detection, which is transmitted to the CPU (not shown).The CPU can distinguish between the signals produced as a result of theemitted light hitting the flat side (111) and the semi-circular side(119) of the distal end of the shaft (128). As can be understood by oneskilled in the art, there can be a multiple number of sides (111)(thereby creating a plurality of partially-circular sides (119)). Asstated above, the monitoring system can include a plurality of LEDs andlight detectors.

FIGS. 13 a-c show an alternate exemplary monitoring system of thedriving mechanism that is based on the “Hall Effect” principle,according to some embodiments of the present invention. The Hall Effectrelates to the formation of a difference in potential between oppositesides of an element composed of a conducting or a semi-conductingmaterial through which an electric current is flowing, whereby amagnetic field is applied perpendicularly to the electric current. Asshown in FIG. 13 a, the monitoring system includes two equally spacedmagnets (92) are either protruding from the secondary gear (124) orembedded inside appropriate apertures or depressions made in the gear(124), and a “Hall effect sensor” (90) positioned on the PCB (130). Ascan be understood by one skilled in the art, there can be any number ofmagnets (92) and sensors (90). Further the magnets (92) can be locatedanywhere on the gears or any other element of the driving mechanism.Referring back to FIG. 13 a, as the secondary gear (124) rotates, themagnets (92) pass by the Hall effect sensor (90) and expose the sensor(90) to their magnetic field. As the magnets (92) pass through thesensor (90), their magnetic field interacts with the electrical currentflowing through the sensor (90), thereby creating a change in theelectrical current (or electro-magnetic field) of the sensor (90). Upondetection of such change, the sensor (90) generates a signal andtransmits it to the CPU or any other component disposed on the PCB (130)for processing.

FIG. 13 b illustrates the situation when one of the magnets (92) locatedon the secondary gear (124) passes vis-à-vis the “Hall effect sensor”(90) and exposes the sensor (90) to its maximum magnetic field. As aresult, the electrical signal transmitted by the “Hall effect sensor”(90) either to the CPU (not shown) or to another electronic component,e.g., a comparator (not shown), peaks. The “1” marked on the “Halleffect sensor” (90) in FIG. 13 b indicates that a peak in thetransmitted electrical signal may be assigned a digital “1” reference.

FIG. 13 c shows a situation when none of the magnets (92) are locatedvis-à-vis the “Hall effect sensor” (90). In this case, the electricalsignal transmitted by the “Hall effect sensor” (90) either to the CPU(not shown) or to another electronic component, e.g., a comparator (notshown), remains constant. The “0” marked on the “Hall effect sensor”(90) in FIG. 13 c indicates that no change in the transmitted electricalsignal may be assigned a digital “0” reference.

FIG. 14 shows another exemplary monitoring system employing the HallEffect sensor (90), according to some embodiments of the presentinvention. In this embodiment, two equally spaced magnets (92) areplaced at the end of the shaft (128) and a “Hall effect sensor” (90) ispositioned to detect the magnetic field of the passing magnets (92). Thesensor (90) can either to face the tip of the shaft (128) without beingcoaxial with the shaft (128), as shown in FIG. 14, or to face thecircumference of the tip of the shaft (128), as illustrated by thedotted line (90′). As the shaft (128) rotates, the electrical signaltransmitted by the “Hall effect sensor” (90/90′) either to the CPU (notshown) or to another electronic component, e.g., a comparator (notshown), will peak when a magnet (92) passes vis-à-vis the “Hall effectsensor” (90/90′) and exposes the “Hall effect sensor” (90/90′) tomagnetic field. Thus, the electrical signal will peak twice for eachrevolution. As can be understood by one skilled in the art, instead oftwo magnets, it is possible to use only one magnet, provided that theoutwardly facing side of the magnet comprises both north and southpoles, and the same desired effect can be achieved. Further, it ispossible to use more than two magnets, which can be equally spaced. Thenumber of magnets determines the resolution of the monitoring, whereaswhen two magnets (or one magnet having two poles) are used, the signalstransmitted by the “Hall effect sensor” (90/90′) will indicate wheneverhalf a turn has been completed, or, when three magnets are used, thesignals transmitted by the “Hall effect sensor” (90/90′) will indicatewhenever one third of a turn has been completed, etc.

FIG. 15 shows another exemplary embodiment of the infusion pump (10),according to the present invention. The shown infusion pump (10) is asyringe-type infusion pump having the reusable part (100) and thedisposable part (200). The disposable part (200) includes the energysupply means (240) and the fluid reservoir (220) provided with adisplaceable rubber seal (414), an inlet port with a self-sealing rubberseptum (215) and an outlet port (213). The inlet port (215) is in fluidcommunication with the reservoir (220) and is used to fill the reservoir(220) with a therapeutic fluid (e.g., insulin). The outlet port (213) isalso in fluid communication with the reservoir (220) and is used fordelivery of fluid to the body of the patient.

The reusable part (100) has the PCB (130), the manual buttons (15), thedriving mechanism having the pinion (122), the secondary gear (124), theworm (126), the shaft (128), a gear wheel (134), and a restrainingcomponent (132). After connection of the reusable part (100) anddisposable part (200), fluid dispensing can be possible. The motor (120)rotates the pinion (122), which is coupled to the secondary gear (124).The teeth of the pinion (122) are meshed with the teeth of the secondarygear (124), so that the teeth of the pinion (122) transmit torque to theteeth of the secondary gear (124) which then rotates in the oppositedirection. The secondary gear (124) and the worm (126) are both mountedon one shaft (128), so that they rotate at the same velocity, asdiscussed above with regard to FIGS. 1 a-14. As shown in FIG. 15, theworm (126) rotates another gear wheel (134), which transfers movement tothe lead-screw shaft of a piston (412). A restraining component (132)prevents the piston (412) from rotating, thus, allowing lineardisplacement of the piston (412). As the piston (412) is shiftedforward, it pushes forward the displaceable rubber seal (414) of thefluid container (220), and fluid flows toward the outlet port (213). Ascan be understood by one skilled in the art, the above-describedmechanism is one of many examples of a syringe-type infusion pumpdriving mechanism. The monitoring of the driving mechanism can becarried out using the LED (112) and the light detector (114), e.g., aphototransistor, located on opposite sides of the secondary gear (124),using the systems and methods discussed above with regard to FIGS. 3-14.

FIG. 16 is a block diagram of an exemplary closed loop system of themonitoring system, according to some embodiments of the presentinvention. The closed loop system (1600) includes a CPU (1602), adriving mechanism (1610), a rotation monitoring device (1608) andalerting components (1604) for executing the feedback process which ispertinent to all the abovementioned embodiments and which includescorrection of the rotation (1606) of the driving mechanism, if such isdesired. The CPU (1602) activates both the driving mechanism (1610) andthe rotation monitoring device (1608). The rotation monitoring device(1608) includes an LED, a light detector, a photointerruptor, a “Halleffect sensor”, etc., as discussed above with regard to FIGS. 3-14. Therotation monitoring device (1608) may be activated continuously or, forexample, in order to minimize energy consumption, periodically based ona predetermined time schedule. When using a stepper motor, for example,the monitoring device may be activated by the CPU only when the CPUsends a pulse train to the motor.

The rotation monitoring device (1608) monitors rotation of at least onecomponent of the driving mechanism (i.e., motor, gear, shaft, etc.) andtransmits a signal produced by the light detector or any other sensor tothe CPU (1602) (or to another electronic component, e.g., a comparator(not shown), which is connected to the CPU). The CPU (1602) thenprocesses the signal received from the monitoring device and derivesfrom it the number of revolutions executed by the motor during apredetermined time period, or during the dispensing of a predeterminedamount of therapeutic fluid, etc. The CPU (1602) computes the number ofrevolutions which should have been executed by the motor according topre-programmed data regarding the amount of therapeutic fluid dispensedin the course of one motor revolution and data inputted by the patientregarding the amount of therapeutic fluid to be infused. The CPUcompares the actual number of executed revolutions with the number ofrevolutions which should have been executed by the motor, and if theyare dissimilar, i.e., if the motor has executed fewer revolutions thannecessary, or more than necessary, the CPU will execute the neededcorrection of the revolution of the driving mechanism. For example, ifthe information derived from the signal transmitted by the monitoringdevice indicates that the motor has executed X rotations in a specifictime period, whereas it should have executed Y rotations in the saidperiod of time, the CPU will send a command to the motor to rotate anextra Z rotations during the following predetermined time period,whereas Z=Y−X. If correction attempts fail, the CPU will alert thepatient via an alerting component located in the reusable part of theinfusion pump and\or the remote control unit. The above mentionedmonitoring devices can also provide a solution to the backflow problemwhich is inherent in rotary peristaltic pumps.

FIGS. 17 a-d show several consecutive positions of the rollers, as shownin FIG. 4), of a positive displacement peristaltic pump (for example,provided with four rollers) during a pumping cycle. FIG. 17 a shows aroller (101) completely compressing the delivery tube (230) against thestator (190) (not shown) after the adjacent roller (104) has finishedcompressing the delivery tube (230) against the stator and has rotatedaway by the rotary wheel (110). FIG. 17 b shows said roller (101) movingalong the delivery tube (230) and compressing the tube (230) against thestator (not shown), thus, positively displacing fluid in a forwarddirection. FIG. 17 c shows two rollers (101), (102) completelycompressing the delivery tube (230) as roller (101) is about to rotateaway from compressing the delivery tube (230). FIG. 17 d shows roller(102) completely compressing the delivery tube (230) after the roller(101) has rotated away from the delivery tube (230). The pumping phasesdepicted in FIGS. 17 a-c are characterized by a constant flow rate andin a forward direction, i.e., the direction of fluid delivery from thereservoir to the body of the patient, while the pumping phase depictedin FIGS. 17 c-d is characterized by no-flow or backflow. In this case,backflow means a flow of therapeutic fluid in the direction opposite tothe direction of forward flow of the fluid.

FIG. 18 is a characteristic graph of fluid flow rate (volume of fluiddelivered over time) during one rotation of a rotary wheel of a positivedisplacement peristaltic pump provided with four rollers, for example.The points marked a, b, c, d on the graph indicate the positions of therollers, as described in FIGS. 17 a-d, which correspond to said markedpoints on the graph (whereas the position of the rollers as illustratedin FIG. 17 a corresponds to the point on the graph marked “a”, and soforth). The section of the graph between points “a” and “c” is the cycleperiod when roller (101) (FIG. 17) is completely compressing thedelivery tube (230), achieving constant forward flow motion. The sectionof the graph between points “c” and “d” is the cycle period when roller(101) (FIG. 17) is moving away from the tube allowing backward flowmotion. The four nadir periods on the graph correspond to the cycleperiods in which the four rollers are leaving the delivery tube (230).

FIG. 19 shows one preferred embodiment for correction of the widelyvarying flow rate during a pump cycle. The LED (112) and the lightdetector (114) are placed on opposite sides of the rotary gear plate(106), which has four equally spaced apertures (127), (127′) (only twoapertures are shown in FIG. 19)—one aperture is disposed between everytwo adjacent rollers (101), (102, (103) (the fourth roller is not shownin FIG. 19). The LED (112) and the light detector (114) can be placed atany desired location on the rotary gear plate (106). When an aperture(127) is aligned with the LED (112) and the light detector (114), thelight is detected by the light detector (114), which then transmitssignals either directly to the CPU (not shown), or to another electroniccomponent, for processing.

As can be understood by one skilled in the art, the same effect can beachieved by placing said apertures (127), (127′) (only two apertures areshown) closer to the center of the rotary gear plate (106) and disposingfour appropriate apertures on the rotary plate (109), so that every twocorresponding apertures are aligned. In this case the LED (112) islocated on the outer side of the rotary gear plate (106) and the lightdetector (114) is located on the outer side of the rotary plate (109),or vice versa, and in order for the light emitted by the LED (112) to becollected by the light detector (114), a pair of apertures (one on therotary gear plate (106) and one on the rotary plate (109)) has to bealigned with the LED (112) and the light detector (114).

The light detector (114) and the LED (112) used may be two separatelylocated components, as illustrated, or fixed adjacently on a commonsupport frame made of an opaque-material package, e.g., aphotointerruptor. As can be understood by one skilled in the art, amonitoring device based on the “Hall effect”, employing magnets and a“Hall effect sensor”, as shown in FIG. 14, can also be applied. As canbe further understood by one skilled in the art, one rotation monitoringdevice, i.e., an LED and a light detector, a photointerruptor, a “Halleffect sensor”, etc. can be used for both monitoring the rotation of thedriving mechanism of the dispensing unit and minimizing the occurrenceof no flow or backflow and its effects on fluid delivery accuracy, orotherwise two separate devices can be used, one for each purpose.

The closed loop system for executing a feedback process for the purposeof minimizing the occurrence of no flow or backflow and its effects onfluid delivery to the patient is similar to the one shown in FIG. 16.The CPU activates both the driving mechanism and the rotation monitoringdevice, which may include an LED and a light detector, aphotointerruptor, a “Hall effect sensor”, etc. The rotation monitoringdevice may be activated continuously, or, in order to minimize energyconsumption, periodically according to a predetermined time schedule.When using a stepper motor, for example, the monitoring device may beactivated by the CPU only when the CPU sends a pulse train to the motor.

The monitoring device monitors rotation of the rotary wheel andtransmits an electronic signal produced by the light detector or othersensor to the CPU (or to another electronic component which is connectedto the CPU). The CPU adjusts rotation speed according to the relativeposition of the rollers and the tube. In case of a stepper motoracceleration is achieved by continuously sending pulse trains to themotor. Acceleration of the rollers motion during no flow or backflowperiods maintains a uniform flow rate. In an alternative embodiment,when a stepper motor is employed the CPU can be programmed to disregardthe pulse trains resulting in no-flow or backflow due to the position ofthe rollers, and not count them in the calculation of total deliveredfluid. In some embodiments, when stepper motor is employed the CPU canadjust the rotation speed according to the relative position of therollers and the tube, and in addition be programmed to disregard thesepulse trains and not count them in the calculation of total deliveredfluid.

Example embodiments of the methods and components of the presentinvention have been described herein. As noted elsewhere, these exampleembodiments have been described for illustrative purposes only, and arenot limiting. Other embodiments are possible and are covered by theinvention. Such embodiments will be apparent to persons skilled in therelevant art(s) based on the teachings contained herein. Thus, thebreadth and scope of the present invention should not be limited by anyof the above-described exemplary embodiments, but should be defined onlyin accordance with the following claims and their equivalents.

1-46. (canceled)
 47. A device for dispensing therapeutic fluid to a bodyof a patient, comprising: a dispensing unit comprising: a reservoircontaining therapeutic fluid; a driving mechanism comprising a motor andone or more gears; a power supply for providing power to at least themotor; electronic components including at least a processor forcontrolling at least the operation of the motor; and a rotation sensoradapted for monitoring the operation of at least one of the motor andthe one or more gears; wherein the dispensing unit is adapted fordispensing the therapeutic fluid according to output of the rotationsensor.
 48. The device according to claim 47, wherein the dispensingunit further comprises: a fluid delivery tube in fluid communicationwith the reservoir; an outlet port for delivering therapeutic fluid tothe patient, the outlet port is in fluid communication with thereservoir via the fluid delivery tube; and a stator elasticallysupported by a spring for interacting with the fluid delivery tube. 49.The device according to claim 48, wherein the one or more gearscomprises: a pinion coupled to the motor and having a plurality ofpinion teeth, the motor causes rotation of the pinion; a secondary gearhaving a plurality of secondary gear teeth for interacting with theplurality of pinion teeth, wherein rotation of the pinion in aparticular direction causes rotation of the secondary gear in anopposite direction; a shaft coupled to the secondary gear and rotatingin the same direction as the secondary gear; a worm disposed on theshaft and rotating in the same direction as the shaft; and a rotarywheel having a plurality of rotary wheel teeth for interacting with theworm, wherein rotation of the worm causes rotation of the rotary wheel.50. The device according to claim 49, wherein the rotary wheel furthercomprises one or more rollers disposed circumferentially at the rotarywheel; wherein upon rotation of the rotary wheel, the one or morerollers are driven by the rotary wheel and interact with the fluiddelivery tube; wherein the fluid delivery tube is disposed between thestator and the one or more rollers such that the one or more rollerssqueezes the delivery tube against the stator and displaces thetherapeutic fluid inside the fluid delivery tube toward the outlet port.51. The device according to claim 47, wherein the rotation sensorcomprises: an energy source for emitting energy; an energy detector fordetecting energy emitted by the energy source; wherein the energy sourceand the energy detector are adapted to detect rotation of at least oneof the one or more gears; wherein the energy detector generates one ormore signals for processing by the processor.
 52. The device accordingto claim 51, wherein the energy is radiation energy.
 53. The deviceaccording to claim 51, wherein the energy is selected from a groupconsisting of: infrared radiation, electromagnetic radiation,electrochemical energy, electromechanical energy, mechanical energy andother energy.
 54. The device according to claim 51, wherein the energydetector is a light detector.
 55. The device according to claim 51,wherein the at least one of the one or more gears is selected from agroup consisting of: a pinion, a secondary gear, a shaft, a worm and arotary wheel.
 56. The device according to claim 51, wherein the at leastone of the one or more gears is provided with an auxiliary elementrotatable by the at least one of the one or more gears.
 57. The deviceaccording to claim 51, wherein the at least one of the one or more gearsincludes one or more openings for passing the emitted energy from theenergy source to the energy detector; wherein upon detection of theemitted energy by the energy detector, the energy detector generates asignal for processing by the processor, the signal indicating that theat least one of the one or more gears has completed at least a portionof its full revolution.
 58. The device according to claim 51, whereinthe energy source and the energy detector are disposed on opposite sidesof the at least one of the one or more gears.
 59. The device accordingto claim 51, wherein the at least one of the one or more gears comprisesa reflective surface; and wherein the energy emitted by the energysource is reflected by the reflective surface for detection by theenergy detector.
 60. The device according to claim 51, wherein theenergy source and the energy detector are disposed on the same side ofthe at least one of the one or more gears.
 61. The device according toclaim 56, wherein the auxiliary element comprises an encoder vanecoupled to a shaft of the at least one of the one or more gears; whereinupon rotation of the shaft, the encoder vane interrupts the energyemitted by the energy source.
 62. The device according to claim 61,wherein the encoder vane is configured as at least one sector selectedfrom a group consisting of: 180 degree sector, 90 degree sector and 45degree sector.
 63. The device according to claim 47, wherein therotation sensor comprises: a “Hall effect” sensor coupled to theprocessor; one or more magnetic elements coupled to at least one of theone or more gears for exposing the “Hall effect” sensor to a magneticfield of the one or more magnetic elements.
 64. The device according toclaim 47, wherein the dispensing unit further comprises: a reusable partcomprising the driving mechanism, the rotation sensor and the electroniccomponents; a disposable part comprising the reservoir; wherein uponconnection of the reusable part and the disposable part, the dispensingunit becomes operational.
 65. The device according to claim 64, whereinthe disposable part further comprises the power supply.
 66. The deviceaccording to claim 51, wherein the energy source emits the energycontinuously.
 67. The device according to claim 51, wherein the sourceof energy emits the energy periodically.
 68. The device according toclaim 47, wherein the rotation sensor and at least some of theelectronic components are disposed on a carrier.
 69. The deviceaccording to claim 68, wherein the carrier comprises a printed circuitboard (‘PCB’).
 70. The device according to claim 47, wherein thedispensing unit further comprises a piston capable of being displacedwithin the reservoir to deliver the therapeutic fluid to the body of thepatient.
 71. The device according to claim 47, wherein the dispensingunit further comprises at least one manual button for controlling atleast one operation of the dispensing unit.
 72. The device according toclaim 47, further comprising a remote control for remotely controllingat least one operation of the dispensing unit.
 73. The device accordingto claim 47, further comprising an alerting component for generating oneor more alerts to the patient.
 74. The device according to claim 47,wherein the dispensing unit comprises a reusable dispensing unitcontaining the driving mechanism and the rotation sensor.
 75. The deviceaccording to claim 74, wherein at least one of the one or more gears ofthe driving mechanism includes one or more openings.
 76. The deviceaccording to claim 75, wherein the rotation sensor comprises: an energysource that passes emitted energy through the one or more openings inthe at least one of the one or more gears; an energy detector fordetecting energy emitted by the energy source through the one or moreopenings; wherein the energy source and the energy detector detectrotation of the at least one of the one or more gears and wherein theenergy detector generates a signal.
 77. The device according to claim78, wherein the dispensing unit comprises a disposable dispensing unitdetachably-connectable to the reusable dispensing unit.
 78. The deviceaccording to claim 77, wherein the disposable dispensing unit comprises:the reservoir; a delivery tube in fluid communication with thereservoir; an outlet port in fluid communication with the reservoir viathe delivery tube; and a stator elastically supported by a spring forinteracting with the fluid delivery tube.
 79. The device according toclaim 78, wherein the driving mechanism of the reusable dispensing unitoperatively couples with the delivery tube of the disposable dispensingunit.
 80. The device according to claim 79, wherein the dispensing unitfurther comprises a power supply coupled to an electronic component,wherein upon connection of the reusable dispensing unit and thedisposable dispensing unit, the dispensing unit is operational fortransfer of the therapeutic fluid to the body of the patient through theoutlet port.
 81. The device according to claim 49, wherein a region ofthe shaft adjacent the worm comprises at least a portion that is flatand at least a portion that is spherical.
 82. The device according toclaim 81, wherein an energy source and an energy detector of therotation sensor are adjacent to one another and positioned such thatthey each face the same side of the shaft.
 83. The device according toclaim 82, wherein energy emitted from the energy source is reflectedfrom the flat side of the shaft and detected by the energy detector. 84.The device according to claim 83, wherein energy emitted from the energysource hits the spherical side of the shaft and scatters away from theenergy detector.
 85. The device according to claim 50, wherein theprocessor adjusts a speed of rotation of the rotary wheel according to aposition of the one or more rollers relative to the delivery tube tomaintain a uniform flow rate.